/**
 * @file
 * lwIP network interface abstraction
 *
 */

/*
 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 *
 * This file is part of the lwIP TCP/IP stack.
 *
 * Author: Adam Dunkels <adam@sics.se>
 *
 */

#include "lwip/opt.h"

#include "lwip/def.h"
#include "lwip/ip_addr.h"
#include "lwip/netif.h"
#include "lwip/tcp.h"
#include "lwip/snmp.h"
#include "lwip/igmp.h"
#include "netif/etharp.h"
#if ENABLE_LOOPBACK
#include "lwip/sys.h"
#if LWIP_NETIF_LOOPBACK_MULTITHREADING
#include "lwip/tcpip.h"
#endif /* LWIP_NETIF_LOOPBACK_MULTITHREADING */
#endif /* ENABLE_LOOPBACK */

#if LWIP_AUTOIP
#include "lwip/autoip.h"
#endif /* LWIP_AUTOIP */
#if LWIP_DHCP
#include "lwip/dhcp.h"
#endif /* LWIP_DHCP */

#if LWIP_NETIF_STATUS_CALLBACK
#define NETIF_STATUS_CALLBACK(n) { if (n->status_callback) { (n->status_callback)(n); } }
#else
#define NETIF_STATUS_CALLBACK(n) { /* NOP */ }
#endif /* LWIP_NETIF_STATUS_CALLBACK */

#if LWIP_NETIF_LINK_CALLBACK
#define NETIF_LINK_CALLBACK(n) { if (n->link_callback) { (n->link_callback)(n); } }
#else
#define NETIF_LINK_CALLBACK(n) { /* NOP */ }
#endif /* LWIP_NETIF_LINK_CALLBACK */

struct netif *netif_list;
struct netif *netif_default;

/**
 * Add a network interface to the list of lwIP netifs.
 *
 * @param netif a pre-allocated netif structure
 * @param ipaddr IP address for the new netif
 * @param netmask network mask for the new netif
 * @param gw default gateway IP address for the new netif
 * @param state opaque data passed to the new netif
 * @param init callback function that initializes the interface
 * @param input callback function that is called to pass
 * ingress packets up in the protocol layer stack.
 *
 * @return netif, or NULL if failed.
 */
struct netif *netif_add(struct netif *netif,
                        struct ip_addr *ipaddr,
                        struct ip_addr *netmask,
                        struct ip_addr *gw,
                        void *state,
                        err_t (* init)(struct netif *netif),
                        err_t (* input)(struct pbuf *p, struct netif *netif))
{
    static u8_t netifnum = 0;

    /* reset new interface configuration state */
    netif->ip_addr.addr = 0;
    netif->netmask.addr = 0;
    netif->gw.addr = 0;
    netif->flags = 0;
#if LWIP_DHCP
    /* netif not under DHCP control by default */
    netif->dhcp = NULL;
#endif /* LWIP_DHCP */
#if LWIP_AUTOIP
    /* netif not under AutoIP control by default */
    netif->autoip = NULL;
#endif /* LWIP_AUTOIP */
#if LWIP_NETIF_STATUS_CALLBACK
    netif->status_callback = NULL;
#endif /* LWIP_NETIF_STATUS_CALLBACK */
#if LWIP_NETIF_LINK_CALLBACK
    netif->link_callback = NULL;
#endif /* LWIP_NETIF_LINK_CALLBACK */
#if LWIP_IGMP
    netif->igmp_mac_filter = NULL;
#endif /* LWIP_IGMP */
#if ENABLE_LOOPBACK
    netif->loop_first = NULL;
    netif->loop_last = NULL;
#endif /* ENABLE_LOOPBACK */

    /* remember netif specific state information data */
    netif->state = state;
    netif->num = netifnum++;
    netif->input = input;
#if LWIP_NETIF_HWADDRHINT
    netif->addr_hint = NULL;
#endif /* LWIP_NETIF_HWADDRHINT*/
#if ENABLE_LOOPBACK && LWIP_LOOPBACK_MAX_PBUFS
    netif->loop_cnt_current = 0;
#endif /* ENABLE_LOOPBACK && LWIP_LOOPBACK_MAX_PBUFS */

    netif_set_addr(netif, ipaddr, netmask, gw);

    /* call user specified initialization function for netif */
    if (init(netif) != ERR_OK)
    {
        return NULL;
    }

    /* add this netif to the list */
    netif->next = netif_list;
    netif_list = netif;
    snmp_inc_iflist();

#if LWIP_IGMP
    /* start IGMP processing */
    if (netif->flags & NETIF_FLAG_IGMP)
    {
        igmp_start( netif);
    }
#endif /* LWIP_IGMP */

    LWIP_DEBUGF(NETIF_DEBUG,
                ("netif: added interface %c%c IP addr ",
                 netif->name[0], netif->name[1]));
    ip_addr_debug_print(NETIF_DEBUG, ipaddr);
    LWIP_DEBUGF(NETIF_DEBUG, (" netmask "));
    ip_addr_debug_print(NETIF_DEBUG, netmask);
    LWIP_DEBUGF(NETIF_DEBUG, (" gw "));
    ip_addr_debug_print(NETIF_DEBUG, gw);
    LWIP_DEBUGF(NETIF_DEBUG, ("\n"));
    return netif;
}

/**
 * Change IP address configuration for a network interface (including netmask
 * and default gateway).
 *
 * @param netif the network interface to change
 * @param ipaddr the new IP address
 * @param netmask the new netmask
 * @param gw the new default gateway
 */
void netif_set_addr(struct netif *netif, struct ip_addr *ipaddr, struct ip_addr *netmask,
                    struct ip_addr *gw)
{
    netif_set_ipaddr(netif, ipaddr);
    netif_set_netmask(netif, netmask);
    netif_set_gw(netif, gw);
}

/**
 * Remove a network interface from the list of lwIP netifs.
 *
 * @param netif the network interface to remove
 */
void netif_remove(struct netif * netif)
{
    if ( netif == NULL )
    {
        return;
    }

#if LWIP_IGMP
    /* stop IGMP processing */
    if (netif->flags & NETIF_FLAG_IGMP)
    {
        igmp_stop( netif);
    }
#endif /* LWIP_IGMP */

    snmp_delete_ipaddridx_tree(netif);

    /*  is it the first netif? */
    if (netif_list == netif)
    {
        netif_list = netif->next;
        snmp_dec_iflist();
    }
    else
    {
        /*  look for netif further down the list */
        struct netif * tmpNetif;
        for (tmpNetif = netif_list; tmpNetif != NULL; tmpNetif = tmpNetif->next)
        {
            if (tmpNetif->next == netif)
            {
                tmpNetif->next = netif->next;
                snmp_dec_iflist();
                break;
            }
        }
        if (tmpNetif == NULL)
        {
            return; /*  we didn't find any netif today */
        }
    }
    /* this netif is default? */
    if (netif_default == netif)
    {
        /* reset default netif */
        netif_set_default(NULL);
    }
    LWIP_DEBUGF( NETIF_DEBUG, ("netif_remove: removed netif\n") );
}

/**
 * Find a network interface by searching for its name
 *
 * @param name the name of the netif (like netif->name) plus concatenated number
 * in ascii representation (e.g. 'en0')
 */
struct netif *netif_find(char *name)
{
    struct netif *netif;
    u8_t num;

    if (name == NULL)
    {
        return NULL;
    }

    num = name[2] - '0';

    for (netif = netif_list; netif != NULL; netif = netif->next)
    {
        if (num == netif->num &&
            name[0] == netif->name[0] &&
            name[1] == netif->name[1])
        {
            LWIP_DEBUGF(NETIF_DEBUG, ("netif_find: found %c%c\n", name[0], name[1]));
            return netif;
        }
    }
    LWIP_DEBUGF(NETIF_DEBUG, ("netif_find: didn't find %c%c\n", name[0], name[1]));
    return NULL;
}

/**
 * Change the IP address of a network interface
 *
 * @param netif the network interface to change
 * @param ipaddr the new IP address
 *
 * @note call netif_set_addr() if you also want to change netmask and
 * default gateway
 */
void netif_set_ipaddr(struct netif *netif, struct ip_addr *ipaddr)
{
    /* TODO: Handling of obsolete pcbs */
    /* See:  http://mail.gnu.org/archive/html/lwip-users/2003-03/msg00118.html */
#if LWIP_TCP
    struct tcp_pcb *pcb;
    struct tcp_pcb_listen *lpcb;

    /* address is actually being changed? */
    if ((ip_addr_cmp(ipaddr, &(netif->ip_addr))) == 0)
    {
        /* extern struct tcp_pcb *tcp_active_pcbs; defined by tcp.h */
        LWIP_DEBUGF(NETIF_DEBUG | LWIP_DBG_STATE, ("netif_set_ipaddr: netif address being changed\n"));
        pcb = tcp_active_pcbs;
        while (pcb != NULL)
        {
            /* PCB bound to current local interface address? */
            if (ip_addr_cmp(&(pcb->local_ip), &(netif->ip_addr)))
            {
                /* this connection must be aborted */
                struct tcp_pcb *next = pcb->next;
                LWIP_DEBUGF(NETIF_DEBUG | LWIP_DBG_STATE, ("netif_set_ipaddr: aborting TCP pcb %p\n", (void*)pcb));
                tcp_abort(pcb);
                pcb = next;
            }
            else
            {
                pcb = pcb->next;
            }
        }
        for (lpcb = tcp_listen_pcbs.listen_pcbs; lpcb != NULL; lpcb = lpcb->next)
        {
            /* PCB bound to current local interface address? */
            if ((!(ip_addr_isany(&(lpcb->local_ip)))) &&
                (ip_addr_cmp(&(lpcb->local_ip), &(netif->ip_addr))))
            {
                /* The PCB is listening to the old ipaddr and
                 * is set to listen to the new one instead */
                ip_addr_set(&(lpcb->local_ip), ipaddr);
            }
        }
    }
#endif
    snmp_delete_ipaddridx_tree(netif);
    snmp_delete_iprteidx_tree(0, netif);
    /* set new IP address to netif */
    ip_addr_set(&(netif->ip_addr), ipaddr);
    snmp_insert_ipaddridx_tree(netif);
    snmp_insert_iprteidx_tree(0, netif);

    LWIP_DEBUGF(NETIF_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
                ("netif: IP address of interface %c%c set to %"U 16_F ".%"U 16_F ".%"U 16_F ".%"U 16_F "\n",
                 netif->name[0], netif->name[1],
                 ip4_addr1(&netif->ip_addr),
                 ip4_addr2(&netif->ip_addr),
                 ip4_addr3(&netif->ip_addr),
                 ip4_addr4(&netif->ip_addr)));
}

/**
 * Change the default gateway for a network interface
 *
 * @param netif the network interface to change
 * @param gw the new default gateway
 *
 * @note call netif_set_addr() if you also want to change ip address and netmask
 */
void netif_set_gw(struct netif *netif, struct ip_addr *gw)
{
    ip_addr_set(&(netif->gw), gw);
    LWIP_DEBUGF(NETIF_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("netif: GW address of interface %c%c set to %"U 16_F ".%"U 16_F ".%"U 16_F ".%"U 16_F "\n",
                                                                netif->name[0], netif->name[1],
                                                                ip4_addr1(&netif->gw),
                                                                ip4_addr2(&netif->gw),
                                                                ip4_addr3(&netif->gw),
                                                                ip4_addr4(&netif->gw)));
}

/**
 * Change the netmask of a network interface
 *
 * @param netif the network interface to change
 * @param netmask the new netmask
 *
 * @note call netif_set_addr() if you also want to change ip address and
 * default gateway
 */
void netif_set_netmask(struct netif *netif, struct ip_addr *netmask)
{
    snmp_delete_iprteidx_tree(0, netif);
    /* set new netmask to netif */
    ip_addr_set(&(netif->netmask), netmask);
    snmp_insert_iprteidx_tree(0, netif);
    LWIP_DEBUGF(NETIF_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("netif: netmask of interface %c%c set to %"U 16_F ".%"U 16_F ".%"U 16_F ".%"U 16_F "\n",
                                                                netif->name[0], netif->name[1],
                                                                ip4_addr1(&netif->netmask),
                                                                ip4_addr2(&netif->netmask),
                                                                ip4_addr3(&netif->netmask),
                                                                ip4_addr4(&netif->netmask)));
}

/**
 * Set a network interface as the default network interface
 * (used to output all packets for which no specific route is found)
 *
 * @param netif the default network interface
 */
void netif_set_default(struct netif *netif)
{
    if (netif == NULL)
    {
        /* remove default route */
        snmp_delete_iprteidx_tree(1, netif);
    }
    else
    {
        /* install default route */
        snmp_insert_iprteidx_tree(1, netif);
    }
    netif_default = netif;
    LWIP_DEBUGF(NETIF_DEBUG, ("netif: setting default interface %c%c\n",
                              netif ? netif->name[0] : '\'', netif ? netif->name[1] : '\''));
}

/**
 * Bring an interface up, available for processing
 * traffic.
 *
 * @note: Enabling DHCP on a down interface will make it come
 * up once configured.
 *
 * @see dhcp_start()
 */
void netif_set_up(struct netif *netif)
{
    if ( !(netif->flags & NETIF_FLAG_UP ))
    {
        netif->flags |= NETIF_FLAG_UP;

#if LWIP_SNMP
        snmp_get_sysuptime(&netif->ts);
#endif  /* LWIP_SNMP */

        NETIF_LINK_CALLBACK(netif);
        NETIF_STATUS_CALLBACK(netif);

#if LWIP_ARP
        /* For Ethernet network interfaces, we would like to send a "gratuitous ARP" */
        if (netif->flags & NETIF_FLAG_ETHARP)
        {
            etharp_gratuitous(netif);
        }
#endif  /* LWIP_ARP */

#if LWIP_IGMP
        /* resend IGMP memberships */
        if (netif->flags & NETIF_FLAG_IGMP)
        {
            igmp_report_groups( netif);
        }
#endif  /* LWIP_IGMP */
    }
}

/**
 * Bring an interface down, disabling any traffic processing.
 *
 * @note: Enabling DHCP on a down interface will make it come
 * up once configured.
 *
 * @see dhcp_start()
 */
void netif_set_down(struct netif *netif)
{
    if ( netif->flags & NETIF_FLAG_UP )
    {
        netif->flags &= ~NETIF_FLAG_UP;
#if LWIP_SNMP
        snmp_get_sysuptime(&netif->ts);
#endif

        NETIF_LINK_CALLBACK(netif);
        NETIF_STATUS_CALLBACK(netif);
    }
}

/**
 * Ask if an interface is up
 */
u8_t netif_is_up(struct netif *netif)
{
    return (netif->flags & NETIF_FLAG_UP) ? 1 : 0;
}

#if LWIP_NETIF_STATUS_CALLBACK
/**
 * Set callback to be called when interface is brought up/down
 */
void netif_set_status_callback(struct netif *netif, void (* status_callback)(struct netif *netif ))
{
    if ( netif )
    {
        netif->status_callback = status_callback;
    }
}
#endif /* LWIP_NETIF_STATUS_CALLBACK */

#if LWIP_NETIF_LINK_CALLBACK
/**
 * Called by a driver when its link goes up
 */
void netif_set_link_up(struct netif *netif )
{
    netif->flags |= NETIF_FLAG_LINK_UP;

#if LWIP_DHCP
    if (netif->dhcp)
    {
        dhcp_network_changed(netif);
    }
#endif /* LWIP_DHCP */

#if LWIP_AUTOIP
    if (netif->autoip)
    {
        autoip_network_changed(netif);
    }
#endif /* LWIP_AUTOIP */

    if (netif->flags & NETIF_FLAG_UP)
    {
#if LWIP_ARP
        /* For Ethernet network interfaces, we would like to send a "gratuitous ARP" */
        if (netif->flags & NETIF_FLAG_ETHARP)
        {
            etharp_gratuitous(netif);
        }
#endif  /* LWIP_ARP */

#if LWIP_IGMP
        /* resend IGMP memberships */
        if (netif->flags & NETIF_FLAG_IGMP)
        {
            igmp_report_groups( netif);
        }
#endif  /* LWIP_IGMP */
    }
    NETIF_LINK_CALLBACK(netif);
}

/**
 * Called by a driver when its link goes down
 */
void netif_set_link_down(struct netif *netif )
{
    netif->flags &= ~NETIF_FLAG_LINK_UP;
    NETIF_LINK_CALLBACK(netif);
}

/**
 * Ask if a link is up
 */
u8_t netif_is_link_up(struct netif *netif)
{
    return (netif->flags & NETIF_FLAG_LINK_UP) ? 1 : 0;
}

/**
 * Set callback to be called when link is brought up/down
 */
void netif_set_link_callback(struct netif *netif, void (* link_callback)(struct netif *netif ))
{
    if (netif)
    {
        netif->link_callback = link_callback;
    }
}
#endif /* LWIP_NETIF_LINK_CALLBACK */

#if ENABLE_LOOPBACK
/**
 * Send an IP packet to be received on the same netif (loopif-like).
 * The pbuf is simply copied and handed back to netif->input.
 * In multithreaded mode, this is done directly since netif->input must put
 * the packet on a queue.
 * In callback mode, the packet is put on an internal queue and is fed to
 * netif->input by netif_poll().
 *
 * @param netif the lwip network interface structure
 * @param p the (IP) packet to 'send'
 * @param ipaddr the ip address to send the packet to (not used)
 * @return ERR_OK if the packet has been sent
 *         ERR_MEM if the pbuf used to copy the packet couldn't be allocated
 */
err_t netif_loop_output(struct netif *netif, struct pbuf *p,
                        struct ip_addr *ipaddr)
{
    struct pbuf *r;
    err_t err;
    struct pbuf *last;

#if LWIP_LOOPBACK_MAX_PBUFS
    u8_t clen = 0;
#endif /* LWIP_LOOPBACK_MAX_PBUFS */
    SYS_ARCH_DECL_PROTECT(lev);
    LWIP_UNUSED_ARG(ipaddr);

    /* Allocate a new pbuf */
    r = pbuf_alloc(PBUF_LINK, p->tot_len, PBUF_RAM);
    if (r == NULL)
    {
        return ERR_MEM;
    }
#if LWIP_LOOPBACK_MAX_PBUFS
    clen = pbuf_clen(r);
    /* check for overflow or too many pbuf on queue */
    if (((netif->loop_cnt_current + clen) < netif->loop_cnt_current) ||
        ((netif->loop_cnt_current + clen) > LWIP_LOOPBACK_MAX_PBUFS))
    {
        pbuf_free(r);
        r = NULL;
        return ERR_MEM;
    }
    netif->loop_cnt_current += clen;
#endif /* LWIP_LOOPBACK_MAX_PBUFS */

    /* Copy the whole pbuf queue p into the single pbuf r */
    if ((err = pbuf_copy(r, p)) != ERR_OK)
    {
        pbuf_free(r);
        r = NULL;
        return err;
    }

    /* Put the packet on a linked list which gets emptied through calling
       netif_poll(). */

    /* let last point to the last pbuf in chain r */
    for (last = r; last->next != NULL; last = last->next)
    {
        ;
    }

    SYS_ARCH_PROTECT(lev);
    if (netif->loop_first != NULL)
    {
        LWIP_ASSERT("if first != NULL, last must also be != NULL", netif->loop_last != NULL);
        netif->loop_last->next = r;
        netif->loop_last = last;
    }
    else
    {
        netif->loop_first = r;
        netif->loop_last = last;
    }
    SYS_ARCH_UNPROTECT(lev);

#if LWIP_NETIF_LOOPBACK_MULTITHREADING
    /* For multithreading environment, schedule a call to netif_poll */
    tcpip_callback((void (*)(void *))(netif_poll), netif);
#endif /* LWIP_NETIF_LOOPBACK_MULTITHREADING */

    return ERR_OK;
}

/**
 * Call netif_poll() in the main loop of your application. This is to prevent
 * reentering non-reentrant functions like tcp_input(). Packets passed to
 * netif_loop_output() are put on a list that is passed to netif->input() by
 * netif_poll().
 */
void netif_poll(struct netif *netif)
{
    struct pbuf *in;

    SYS_ARCH_DECL_PROTECT(lev);

    do
    {
        /* Get a packet from the list. With SYS_LIGHTWEIGHT_PROT=1, this is protected */
        SYS_ARCH_PROTECT(lev);
        in = netif->loop_first;
        if (in != NULL)
        {
            struct pbuf *in_end = in;
#if LWIP_LOOPBACK_MAX_PBUFS
            u8_t clen = pbuf_clen(in);
            /* adjust the number of pbufs on queue */
            LWIP_ASSERT("netif->loop_cnt_current underflow",
                        ((netif->loop_cnt_current - clen) < netif->loop_cnt_current));
            netif->loop_cnt_current -= clen;
#endif      /* LWIP_LOOPBACK_MAX_PBUFS */
            while (in_end->len != in_end->tot_len)
            {
                LWIP_ASSERT("bogus pbuf: len != tot_len but next == NULL!", in_end->next != NULL);
                in_end = in_end->next;
            }
            /* 'in_end' now points to the last pbuf from 'in' */
            if (in_end == netif->loop_last)
            {
                /* this was the last pbuf in the list */
                netif->loop_first = netif->loop_last = NULL;
            }
            else
            {
                /* pop the pbuf off the list */
                netif->loop_first = in_end->next;
                LWIP_ASSERT("should not be null since first != last!", netif->loop_first != NULL);
            }
            /* De-queue the pbuf from its successors on the 'loop_' list. */
            in_end->next = NULL;
        }
        SYS_ARCH_UNPROTECT(lev);

        if (in != NULL)
        {
            /* loopback packets are always IP packets! */
            if (ip_input(in, netif) != ERR_OK)
            {
                pbuf_free(in);
            }
            /* Don't reference the packet any more! */
            in = NULL;
        }
        /* go on while there is a packet on the list */
    }
    while (netif->loop_first != NULL);
}

#if !LWIP_NETIF_LOOPBACK_MULTITHREADING
/**
 * Calls netif_poll() for every netif on the netif_list.
 */
void netif_poll_all(void)
{
    struct netif *netif = netif_list;

    /* loop through netifs */
    while (netif != NULL)
    {
        netif_poll(netif);
        /* proceed to next network interface */
        netif = netif->next;
    }
}
#endif /* !LWIP_NETIF_LOOPBACK_MULTITHREADING */
#endif /* ENABLE_LOOPBACK */
